# HashTable Review

## This page is review of the HashTable

A Hash table is defined as a data structure used to insert, look up, and remove key-value pairs quickly.

#### Rules of HashTables

- A hash table's load factor is determined by how many elements are kept there in relation to how big the
table is.
- A Function that translates keys to array indices is known as a hash function.
- For lookup, insertion, and deletion operations, hash tables have an average-case time complexity of O(1).
Yet, these operations may, in the worst case, require O(n) time, where n is the number of elements in the
table.

#### Hash Table Properites

Hash Table: array that contains(key,value) pairs
Table Size: current capcity(array Length)
Load Factor: ^{(Number of Key Value Pairs in Table)}⁄_{(Table Size)}
#### Choosing a Hash Function

To ensure that the number of collisions is kept to a minimum, a good hash function should distribute the keys
throughout the hash table in a uniform manner.
To enable speedy hashing and key retrieval, the hash function should be efficient.
A hash function should be flexible enough to adjust as the data being hashed often changes.
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